The goals of the second year are to continue to enhance our understanding of how monkeys may operantly manipulate precentral neurons and further clarify factors which influence their ability to produce that control. In an attempt to standardize the paradigm, the effects of audio and visual feedback in the monkey's acquisition of, and operant control over, neurons will continue to be investigated. The potent advantage of this method of operant control is that the monkey is undrugged and an active participant in experiments. The proposal describes a standardized single unit conditioning paradigm capable of quantifying the monkey's control of physiologically identified single neurons in precentral cortex. We would like to determine to what extent the neurons' responses are secondary to a more general phenomena as opposed to the monkey using specific peripheral to central pathway. Use of bilateral recording mounts over precentral cortex will allow recording of two neurons simultaneously.